Some electronic equipments have internal switches installed inside the equipments. Thus, a housing of such an electronic equipment is provided with an opening for use in manipulating the internal switches from the outside of the housing. Further, such an electronic equipment is conventionally equipped with a dustproof structure for preventing dust particles or the like from entering the housing thereof, and the opening is configured such that it can be opened only when operating the internal switches.
Japanese Utility Model Laid-open Publication No. H5-78295 discloses an example of such a dustproof structure for use in a conventional electronic equipment, e.g., a receiver of a radio controller.
FIGS. 6 to 8 illustrate the receiver of the radio controller disclosed in Japanese Utility Model Laid-open Publication No. H5-78295 (hereinafter, simply referred to as a radio control receiver). Specifically, FIG. 6 is a plan view of the radio control receiver; FIG. 7 is a side view thereof; and FIG. 8 sets forth a plan view of the receiver from which a cover is opened.
As shown in the figures, the radio control receiver 10 includes an approximately box-shaped housing 20. Provided in a lateral surface of the housing 20 are terminals 30 connected to a servo mechanism for driving a power supply battery or a driving unit of an object to be controlled. Also, a linear antenna 40 is drawn out to be extended from the inside of the housing 20 through a lateral surface thereof.
Moreover, a circuit board (not shown) forming a receiver circuit is disposed in the housing 20, and a pair of rotary type dual inline package switches (hereinafter referred to as “DIP switches”) 50 for switching a receive frequency of the radio control receiver 10 are mounted on the circuit board as internal switches. Further, an opening 20a is provided at the housing 20 at a position corresponding to the DIP switches 50 to expose the DIP switches 50 to the outside.
A translucent cover 60 formed of, e.g., a resin material is installed in the housing 20 to be freely slidable over the opening 20a. The cover 60 is of a substantially rectangular shape of a size large enough to cover the opening 20a completely. A cross section of the cover 60 along a direction parallel to a shorter side thereof is of a substantially trapezoid shape, and the cover 60 is installed in the housing 20 to be protruded therefrom. Further, guide grooves 60a are formed at both shorter lateral surfaces of the cover 60.
In addition, protruded portions 20b are formed in the housing 20 along both shorter sides of the opening 20a. By locking the guide grooves 60a of the cover 60 with the protruded portions 20b, the cover 60 can be configured to be slidable with respect to the housing 20.
In this configuration, when operating the DIP switches 50, the cover 60 is slid off the openings 20a to thereby expose the DIP switches 50 for a user to operate them. When the DIP switches 50 need not be operated, the cover 60 is closed to prevent intrusion of dust or the like from outside.
As for such a conventional dustproof structure for the electronic equipment, however, since the cover is installed in the housing of the electronic equipment such that it is protruded to be entirely exposed to the outside, a user's finger or an object can happen to make an unintended contact with the cover to exert an excessive force. At this time, if an excessive load is exerted on the cover such that the cover can be separated from the housing or be damaged.
Moreover, with the recent technological advances, various electronic components included in an electronic equipment are greatly reduced in their sizes and thus the size of the electronic equipment itself is getting smaller as well, while providing same functions.
However, in the conventional dustproof structure for use in the electronic equipment, since the entire cover is attached on the housing as mentioned above, the cover portion may protrude higher than the other surface portion on the same plane. Therefore, the presence of the cover would be an obstacle to the size reduction of the electronic equipment.